An image forming apparatus forms a toner image on a transfer belt using a developing unit, transfers the toner image formed on the transfer belt to a printing medium, and fixes the toner image to the printing medium with heat and pressure, thereby forming an image on the printing medium. An image transfer unit of the image forming apparatus has a plurality of process units for forming a toner image on a transfer belt with toners of different colors. The image forming apparatus performs printing (monochrome printing) in a monochrome mode in which a single color (monochrome) image is formed on a printing medium, using one of the plurality of process units. Further, the image forming apparatus performs printing (color printing) in a color mode in which a plurality of color images are formed on a printing medium, using the process units.
When performing the monochrome printing, the image forming apparatus sets the image transfer unit in the monochrome mode (monochrome position). The monochrome position is a state where a photoconductive drum of the process unit used for printing contacts with the transfer belt and a photoconductive drum of the other process unit is away from the transfer belt. Further, when performing the color printing, the image forming apparatus sets the image transfer unit in the color mode (color position). The color position is a state in which photoconductive drums of all the process units are in contact with the transfer belt. In the image forming apparatus, either the monochrome mode or the color mode is set as a reference mode (home position). In a state (ready state) in which printing can be performed, the image forming apparatus sets the plurality of process units of the image transfer unit to a state corresponding to the reference mode, and waits for a print instruction. Further, when receiving the print instruction in a mode different from the reference mode, the image forming apparatus performs a process (initialization process) of switching the image transfer unit to a position corresponding to the instructed mode.
However, when a frequently used mode is different from the reference mode, the frequency of the initialization process may increase, and the time to wait for the completion of the initialization process may increase.